In a victory for the makers of frozen pizzas, tomato paste and French fries, Congress on Monday blocked rules proposed by the Agriculture Department that would have overhauled the nation’s school lunch program.

The proposed changes — the first in 15 years to the $11 billion school lunch program — were meant to reduce childhood obesity by adding more fruits and green vegetables to lunch menus, Agriculture Department officials said.

The rules, proposed last January, would have cut the amount of potatoes served and would have changed the way schools received credit for serving vegetables by continuing to count tomato paste on a slice of pizza only if more than a quarter-cup of it was used. The rules would have also halved the amount of sodium in school meals over the next 10 years.

But late Monday, lawmakers drafting a House and Senate compromise for the agriculture spending bill blocked the department from using money to carry out any of the proposed rules.

In a statement, the Agriculture Department expressed its disappointment with the decision.

“While it is unfortunate that some in Congress chose to bow to special interests, U.S.D.A. remains committed to practical, science-based standards for school meals that improve the health of our children,” the department said in the statement.

Food companies including ConAgra, Coca-Cola, Del Monte Foods and makers of frozen pizza like Schwan argued that the proposed rules would raise the cost of meals and require food that many children would throw away.

The companies called the Congressional response reasonable, adding that the Agriculture Department went too far in trying to improve nutrition in school lunches.

“This is an important step for the school districts, parents and taxpayers who would shoulder the burden of U.S.D.A.’s proposed $6.8 billion school meal regulation that will not increase the delivery of key nutrients,” said John Keeling, executive vice president and chief executive of the National Potato Council.

The Agriculture Department had estimated that the proposal would have cost about $6.8 billion over the next five years, adding about 14 cents a meal to the cost of a school lunch.

Corey Henry, a spokesman for the American Frozen Food Institute, said the proposed rules simply did not make sense, especially when it came to pizza.

The industry backs the current rules which say that about a quarter-cup of tomato paste on a slice of pizza can count as a vegetable serving. The Agriculture Department proposal would have required that schools serve more tomato paste per piece of pizza to get a vegetable credit, an idea the industry thought would make pizza unappetizing.

The department said the change would have simply brought tomato paste in line with the way other fruit pastes and purees were credited in school meals.

Nutrition experts called the action by Congress a setback for improving the nutritional standards in school lunches and addressing childhood obesity.

“It’s a shame that Congress seems more interested in protecting industry than protecting children’s health,” said Margo G. Wootan, director of nutrition policy at the Center for Science in the Public Interest, a nonprofit research group. “At a time when child nutrition and childhood obesity are national health concerns, Congress should be supporting U.S.D.A. and school efforts to serve healthier school meals, not undermining them.”

A version of this article appeared in print on November 16, 2011, on page A21 of the New York edition with the headline: Congress Blocks New Rules on School Lunches.